Different kinds of sensors serving as user interfaces and devices, such as mobile devices, are known in the art for sensing an input action of a user. In standard touch sensors, the input is performed by touching a sensor surface with a finger or stylus. In this way, these touch sensors provide a user interface or man-machine interface to control various functions of the device having a touch sensor incorporated therein.
Known touch sensors work by reacting to a change in resistance or capacitance affected by the presence of a finger or stylus of a user. A capacitive touch sensor or touch screen panel is a sensor typically made of glass coated with a transparent conductor. For example, known touch sensors, e.g. available from Cypress Semiconductor, comprise two layers with capacitive components, wherein these components are connected with each other horizontally in the first layer and vertically in the second layer to provide a matrix structure enabling to sense a position in x,y-coordinates of where the sensor is touched. In capacitive touch panels, the capacitive components of one layer forms one electrode of a capacitor and the finger or stylus forms another electrode.
Recent applications, such as multi-touch applications, require that more than one position on a touch sensor is touched and sensed, e.g. to determine a section of an image on a display that is to be magnified. As applications become more complex, new improved user interfaces are needed that allow additional input parameters.
For example, it is envisaged to use the force applied from the finger to a touch panel of a touch sensor as an input parameter.
Therefore, it is desirable to provide a touch sensing apparatus, mobile device and method for touch operation sensing, which allow to reliably sense an applied force.